| Nygaard & Co AS | Professional & scientific | 1987 |
| Odd Strand AS | Administrative & support | 2022 |
| Olav Rygge AS | Administrative & support | 2019 |
| Ole Jørgen Fjeldstad AS | | 2018 |
| Omega Sol Holding AS | Manufacturing | 2023 |
| Omega Solskjerming AS | Manufacturing | 2023 |
| Opiri Utvikling AS | Real estate | 2022 |
| Optimal-Økonomi AS | Professional & scientific | 2017 |
| Orderinvest Norlag AS | Wholesale & retail | 1989 |
| Orgelhuset AS | Wholesale & retail | 2025 |
| Oslo Services Sjøen AS | Professional & scientific | 1994 |
| Oslo Taxi & Transport AS | Transport & logistics | 2024 |
| Oslo Urmakerservice AS | Other services | 2015 |
| Ovs AS | Construction | 2017 |
| Owrum Bygg Og Blikk AS | Construction | 2019 |
| Oyster & Anchor AS | Professional & scientific | 2012 |
| Oyster & Anchor Holding AS | | 2019 |
| P.A. Torp Holding AS | | 2024 |
| Pass Partner Nuf | Wholesale & retail | 2011 |
| Peh Holding AS | | 2018 |
| Per Weums Trafikkskole AS | Education | 1995 |
| Perfetto Eiendom AS | Real estate | 2020 |
| Pigernes Blomster & Glæder Ans | | 1989 |
| PJK Invest AS | Real estate | 2005 |
| Plateteknikk AS | Manufacturing | 2003 |
| Pompel Og Pilt, Pust Og Pes Da | Administrative & support | 2024 |
| Predita AS | Wholesale & retail | 2016 |
| Prestby Rør AS | Construction | 2015 |
| Prodib AS | Wholesale & retail | 2019 |
| Promaling AS | Construction | 2026 |
| PS Montasje AS | Construction | 2022 |
| Pso Regnskap AS | Professional & scientific | 2004 |
| Public Institution Baltic Innovation Group | Professional & scientific | 2007 |
| På Lag Med AS | Administrative & support | 2017 |
| Pål Westby AS | Information & communication | 1990 |
| Quality Group Invest AS | Professional & scientific | 2014 |
| Quietly AS | Wholesale & retail | 2023 |
| R Malmberg AS | Real estate | 2005 |
| Radio Og TV - Hvitevareservice AS | Wholesale & retail | 2025 |
| Rawfor Øst AS | Wholesale & retail | 2022 |
| RC Modellflysport AS | Wholesale & retail | 2018 |
| Reklamedesign AS | Professional & scientific | 2008 |
| Rekron AS | Administrative & support | 2012 |
| Rekron Industrigummi AS | Wholesale & retail | 2014 |
| Renholdshjelpen AS | Administrative & support | 2026 |
| Respons Partner AS | Information & communication | 1997 |
| Ringstad Holding AS | Real estate | 2003 |
| Rola Holding AS | Wholesale & retail | 2020 |
| RR Bygg AS | Professional & scientific | 2009 |
| RR Eiendom Jerikoveien 26 AS | Professional & scientific | 2011 |
| RR Holding AS | Transport & logistics | 2009 |
| Rsh-Invest AS | | 2017 |
| Rør, Varme & Kjøling AS | Construction | 2026 |
| Rørleggerfirmaet Lars Pettersen AS | Construction | 2012 |
| Rørleggerservice AS | Construction | 2024 |
| Rørleggertjenesten Spydeberg AS | Construction | 2011 |
| Sagtun Lager AS | Real estate | 2019 |
| Sak-Eiendom AS | Wholesale & retail | 2014 |
| Sak-Holding AS | Wholesale & retail | 2014 |
| Salario AS | Professional & scientific | 2025 |
| Sandrian AS | | 2021 |
| Scanflex AS | Wholesale & retail | 1999 |
| Schaug's Invest AS | | 2022 |
| Schiegaarden AS | Hospitality | 2023 |
| SD Byggentreprenør AS | Construction | 2019 |
| Sea-Tek AS | Manufacturing | 2021 |
| Sea-Tek Eiendom AS | Real estate | 2009 |
| Service Pro AS | Construction | 2025 |
| Servicecapital AS | Professional & scientific | 2017 |
| Servietten AS | Real estate | 2005 |
| Sesam Bygg Og Rør Ans | Real estate | 1999 |
| SGC Coating AS | Manufacturing | 2022 |
| Sigurdsgate Utvikling AS | Real estate | 2023 |
| Silverdalen Holding AS | Construction | 2022 |
| SK Service AS | Wholesale & retail | 2013 |
| Skolegaten 7 AS | Real estate | 2005 |
| SLK Bygg AS | Construction | 2025 |
| SLK Facility Management AS | Administrative & support | 2026 |
| SLK Innregulering AS | Construction | 2025 |
| SLK Montasje AS | Construction | 2025 |
| SLK Rør AS | Construction | 2026 |
| Sløyden AS | Hospitality | 2016 |
| Småbyen Spydeberg SA | Other services | 2014 |
| Snauklipp AS | Other services | 2021 |
| Sofima Holding AS | | 2024 |
| Sol Eiendom Og Drift AS | Real estate | 2011 |
| Solend Holding AS | | 2022 |
| Solsiden Barnehage SA | Education | 1989 |
| Sorgverten AS | Hospitality | 2017 |
| Speil - O - Glass AS | Real estate | 1969 |
| Spiv AS | Real estate | 2023 |
| SPV162 AS | Real estate | 2025 |
| Spydeberg Bakeri & Konditori AS | Manufacturing | 1991 |
| Spydeberg Bil AS | Wholesale & retail | 2017 |
| Spydeberg Bilverksted AS | Other services | 2012 |
| Spydeberg Bruktbil AS | Wholesale & retail | 2023 |
| Spydeberg Byggentreprenør AS | Construction | 2012 |
| Spydeberg Elektro AS | Construction | 2008 |
| Spydeberg Grunneierlag SA | Real estate | 1952 |
| Spydeberg Konditori Ans | | 1991 |